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The health condition of spruce stands in the Moravian-Silesian Beskids is affected by several predisposition factors, the most important of which is the allochthonous character of spruce grown on improper sites. When exposed to a low supply of nutrients and intensive mechanical damage mainly by game, the trees are susceptible to rot infestations, climatic agents and mechanical destruction by snow, hard rime and wind. At present, air pollution does not show any significant impact on the spruce stands; it rather acts as a less important predisposition factor on mountain peaks. The physiological condition of trees is not impaired to the extent which would facilitate infestation with phytophagous or cambioxylophagous insects.
Ips duplicatus adults were sampled with pheromone-baited black window-slot traps (Theysohn) in 70- to 100-yearold Norway spruce (Picea abies) stands between 280 and 650 m a.s.l. in the eastern Czech Republic and southern Poland during 2000– 2010. Sets of 5–12 traps were placed about 20 m from the edge of the infested forest. Each trap was baited with a standard synthetic pheromone lure (ID Ecolure), and was setup 1.5–2.0 m above the ground. The objectives were to determine the relationship between the numbers of adults trapped in the overwintered generation and those in the offspring generation. According to data from 135 traps, the numbers of overwintered beetles captured in spring (April–June) were significantly higher than the numbers captured in summer (July–August), but the numbers of offspring beetles captured in summer were significantly correlated with the numbers overwintered beetles captured in spring. The spring captures can be used to estimate the threat caused by I. duplicatus during the whole vegetation season. The traps installed in summer should be used to determine the peaks in the bark beetle flight activity, thus enabling early identification of trees infested by I. duplicatus, especially inside stands.
Recently, the population of Eumodicogryllus bordigalensis consisting of more than ten males has been observed in Novosedly railway station in the most south-eastern part of the Czech Republic during 2004-2006. The individuals occupied railway embankment composed of coarse grit. Single male was found on other place at Mušlov sand pit. In southern Moravia, this species probably occurs on the northern edge of its range. The adults occur from the beginning of June to the beginning of September. The calling song of males of E. bordigalensis from Novosedly consists of long, uninterrupted sequence of syllables which lasts several minutes. The normal duration of syllables were 0.122-0.149 s, they are consisted of 11-13 impulses and the carrier frequency shows a band between 4.6-15.5 KHz.
Trypodendron laeve has a disjunctive distribution and was unknown until recently in most of Europe, where it is now considered by some sources to be an alien pest. The abundance of all four Trypodendron species in Europe (T. laeve, lineatum, domesticum, and signatum) was monitored with traps containing the aggregation pheromone lineatin, which attracts all four species, in 70- to 100-year-old Norway spruce stands in 10 study areas (seven in the Czech Republic and three in Poland). Pheromone-baited, black, window-slot traps (Theysohn, Germany) were deployed (1 to 5 per site) from mid-March/early-April to late-May/early-June. Three Trypodendron species were captured (20,040 beetles). T. lineatum was the most abundant (n = 16,922), followed by T. laeve (n = 2,686) and T. domesticum L.) (n = 432); T. signatum was not detected. T. laeve was detected in three of seven study areas in the Czech Republic over the 3 years of monitoring. Although T. laeve had been detected in Poland during preliminary monitoring in 1988, it was not detected in the three study areas in Poland in the current study. The abundances of T. laeve males and females did not significantly differ in the Czech Republic. The abundance of T. lineatum was correlated with the abundance of T. laeve in the same traps. Although T. laeve has an extensive distribution, its abundance is generally low. Because the species is widely distributed in Europe, there is no practical reason to consider it alien pest in this region.
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